About Lake Levels

How do we measure lake levels?
Lake levels are a relative measure, not the actual depth of the lake. Lake levels
tells us the difference between the current level of the lake and full pond.
We consider full pond the point at which the water begins to spill over the
flood gate or spillway. For the purposes of lake levels, we call this level
100.0 feet.

Lake levels are updated about every twenty minutes.

Lake levels are measured at the hydrostation dam.

Levels are expressed in feet in relation to full pond, where full pond is
100.0 feet.

Full pond elevation is equivalent to the top of the flood gates at gated
impoundments and the top of the open spillway at lakes that do not have gates.

Lake levels fluctuate daily and seasonally due to hydroelectric generation
and weather conditions. Lake levels may vary within the normal operating range,
and the normal minimum or maximum elevation may occur at any time during the
identified month. Lake levels may vary depending on your location on the reservoir.

Actual
This is the latest lake level reading.

Target
We forecast appropriate lake levels according to the season, taking into consideration
such factors as typical rainfall, expected power usage and others. The target
number represents where we expect to be on the current date. The actual number
often differs to meet current conditions.

Min.
By setting a range, we ensure that the lakes meet the expectations of the community.
This is the lowest level for the current date.

Max.
The highest level for the current date.

Low Inflow Stage (LIP)
The Low Inflow Protocol (LIP) establishes procedures for reductions in water use during periods of
low inflow. The LIP was developed on the basis that all parties with interests in water quantity
will share the responsibility to establish priorities and to conserve the limited water supply.
This Low Inflow Protocol provides trigger points and procedures for how Duke’s hydro generation
projects will be operated as well as water withdrawal reduction measures and goals for other water
users during periods of low inflow. As hydrologic conditions worsen, Duke will declare various
stages (0-4)(NA=0) of a low inflow condition where each stage calls for greater reductions in hydro
station releases and water withdrawals.

Range
The range link shows a graph of the minimum and maximum levels over a period
of time.
AMSL - The term above mean sea level (AMSL) refers to the elevation (on the ground) or
altitude (in the air) of any object, relative to the average sea level.

Lake Message
When conditions warrant, it may be necessary to operate the hydro dams or lakes
in uncommon ways. Examples include during prolonged periods of heavy rainfall
when the dams may be prone to spill or during dry seasons when the reservoir
is not replenished in a timely manner. Check here for messages that will let
you know what to expect.